Laminar flow diffusers are located in the ceiling of a room immediately above a work area and deliver a controlled downward flow of conditioned supply air with minimal entrainment of residual room air. The low entrainment of residual room air results from the low initial face velocity of the air delivered by the laminar flow diffuser. The uniform low velocity downward projection of supply air through a diffuser face, combined with low-level exhaust or return air inlets, is ideal for industrial clean rooms or hospital operating rooms. The boundary layer of the air mass in the room is the only place where any appreciable entrainment of residual room air may occur. With the boundary layer, remote from the work area, the low velocity controlled air mass delivered from the laminar flow diffuser effectively isolates the work area from any effects or contaminants of the residual room air.
Laminar flow diffusers typically have a full flow butterfly style dampers to control the amount of air delivered downwardly through the diffuser face to the room below. The laminar flow diffusers are typically configured and sized for either ceiling surface mount or for ceiling T-bar installation.
Because of the low flow of the laminar flow diffusers, a substantial portion of the ceiling may be occupied by the laminar flow diffusers. Such a construction creates a possible trade-off between the ceiling area allocated to the laminar flow diffusers and the ceiling area allocated to lighting fixtures. Such a trade-off becomes particularly acute in work areas that require a high degree of illumination as well as a low degree of contaminant entrainment, such as hospital operating rooms or industrial clean rooms.